Radio malfunctioning after battery disconnect

[JPW]

Hi all,

I've come here concerning a strange issue I've encountered after doing some maintainance on my 406 coupé. Since I'm a Dutchie, I've already asked my fellow owners on the nation forum, however we've run out of ideas.

It started around the holidays when my clutch went out. I figured I'd use my time off to replace it, so I did. It took me about five days to pull it off due to Christmas and all kinds of fun. During the process, the battery was disconnected because I didn't want any wires in the way. Upon completing the job I reconnected the battery and started the car. The new kit was working perfectly, but my radio however, was not. It didn't work at all anymore, and it hasn't ever since. It simply doesn't respond to anything at all.

So recently, I decided to try out a few things based on some suggestions of me and my fellow Dutchies. I'll list them below:

- Checked fuses and wires, nothing out of the ordinary.
- Tried a 'BSI soft reset'. Nothing.
- Used my PP2000 to read any errors. Both radio and dashboard produced "No communication with display possible". I figure the radio needs the connection to function properly.
- Using PP2000, reconfigured the radio. No luck.
- Using PP2000, used the 'testing' function. Radio suddenly turned on, but doesn't respond to any controls, neither on the unit itself, or steering wheel controls. Also, the display doesn't produce any info other than temperature, milage info and time. It seems to me that there's truly no connection between the two units.
- Switched displays with one I have laying around somewhere. Screen is perfectly fine, but nothing changes.
- Switched head units with my dad's 406 sedan (both clarion), tried testing with PP2000 again, no difference at all. Exact same behaviour.

So basically, I've ruled out any problems with fuses, power supply, the radio itself and the display. Like I said, me and my fellow coupé-owners have run out of ideas. Often, a couple of them lend some knowledge from here, so I thought I'd give it a go. Hopefully any of you can shed some light on my situation.

Many thanks in advance.

[GingerMagic]

Did someone suggest the yellow relay behind the radio..??

This can be bypassed.

[JPW]

I don't believe I've tried that, neither am I familiar with any relay being there. Where would I be looking exactly? And what does the relay do that could have it causing this problem?

[Rolebama]

Bit obvious, but have you coded it?

[JPW]

I take it you mean programming the VIN into the unit through the PP2000? In that case, yes.

[GingerMagic]

I've copied this from he 406 coupe forum....

' Finally got down to sorting my non-functioning OE Clarion. No response to the on/off switch, no sounds, no response on the MFD. Traced the problem to a relay-like bright yellow plastic unit marked "FACON", "FILTRE", "96 386 035 80", located behind the centre console just under the radio. My limited French identifies this as a filter, Three wires go into the multi-plug; yellow/green (earth), purple (permanent 12v +ve), orange (output to pin 7 of the ISO connector into the head unit). No voltage on the orange wire, so I remove the filter and fit a jump wire to connect the purple and orange on the multi-plug. Hey presto, my radio works!
So the question is, what does this filter do and is it essential? '

Hope this helps....

[JPW]

I know exactly what you're talking about, and it seems like it's the exact same problem I'm experiencing. I'll check the bastard out tomorrow.

[Rolebama]

I am wondering if the yellow gizmo is a 'choke'. Stops electrical interference from affecting radio through power source wire. (Does away with the need for any suppressors, and I remember having to fit suppressors on alternators, wiper motors, heater motors, electric aerials, windscreen washer motors etc etc.)

[Doggy]

No doubt it will contain a choke - some form of RLC filter I imagine.

[JPW]

Hi Guys, I found the yellow filter and bypassed it, no luck.

I also looked up the reason it could have worked. It's indeed an RLC filter thats supposed to remove any interference from the power supply. If the filter fails at some point, the power supply to the radio is cut. My radio's lights are working however, and it is able to turn on through the testing function on the PP2000. So I didn't expect much anyway.

Yesterday I took out the PP2000 to check out a different issue and thought I'd use my time in to investigate the radio issue a bit further. Found the following additional results:

- No communication from radio to display.
- No communication from display to dashboard
- No communcation from dashboard through data cable.
- No communication from BSI to display

Seems like the display causes a load of trouble, but I already swapped it for a different one. I'm starting to believe I might have caused some trouble with my BSI, mainly because all these problems started occurring after unplugging my battery for 5 days..

So once more, any thoguhts?

[steve_earwig]

Any chance of the build code (aka RPO/DAM)? Failing that the chassis number.

- No communication from radio to display. - Well, as the radio is dead...
- No communication from display to dashboard - Umm, they need to communicate?
- No communcation from dashboard through data cable. - You can't access the instrument panel through PP?
- No communication from BSI to display - interesting.

[JPW]

DAM number is 9227U5.

Display is producing Date/milage information (mpg, etc), exterior temperature, and time. It also displays info messages such as running low on fuel or switching the auto-headlights function. However, no radio related information, not even when the radio turns on through the PP2000 test function.

The 'no communications' messages are retrieved from the PP2000 error code readings on my laptop. I do have access to all the units.

Sidenote: I figure the dash and display need to communicate to produce milage information on the display, which it actually dóes do strangely.

[steve_earwig]

Ah, thanks. I deleted the question about the display because I read your first post again, thanks for the clarification though.

Communication between the radio, the display and the BSI is MUX (run for the hills!), it's the same circuit but this also includes temperature, which is showing, so I suspect the MUX is ok.

I'm trying to work out if hitting the radio on/off switch alerts the BSI and the BSI turns it on, or if it works in the sensible way, on/off switch turns the radio on and doesn't care about the BSI. Answers on a post card to the usual address.

You're getting two lives on BH10 & AH25B and an earth on M841? You probably checked this back in January but I have to ask.

[steve_earwig]

Oh, it's all very well me clicking off hifi (amplifier) and cd changer but does it have any of these things or is it a standard single slot cd player?

[JPW]

Not familiar with any HiFi equipment being in the car. I've got a coupé pack edition, equipped with a JBL speakerset: 8 speakers and an extra amp in the trunk. How would I go about checking HiFi?

Also, I have a headunit with tape player. There used to be a cd-changer connected to it, but i swapped it out for a Connects2 USB module. I've equipped the USB module with the extra bluetooth module from connects2 aswell, which is showing a blue light as its supposed to, telling me the system is recieving power if that helps.

As for the 'lives on BH10 & AH25B and an earth on M841', I have no clue what you're talking about. I suppose they're certain pins on the connectors going in the rear of the head unit, but I havent checked any of those. Which ones are they, and how do I check them? I am familiar with using a circuit tester, just unfamiliar with any codes.

Lastly, I'm almost sure the radio alerts the BSI before turning on, based on the following fact:
The 406 has an 'Eco mode', I'm sure you're familiar with it. Whenever any accessories are left turned on for about 20 minutes, the BSI picks up on it and shuts it off, displaying 'Eco Mode' on the display. The car will remain in said mode until the engine is turned on again. So whenever the Eco Mode has been engaged, the radio will not turn on, and display the same message. So how does the radio know about the eco mode being active? My guess is the BSI tells the unit after attempting to switch on. Hence I believe there's communication between the two units before allowing it to be turned on.